Camera flasher systems



H. SCHANKLER 3,116,671

Jan. 7, 1964 CAMERA FLASHER SYSTEMS Filed Oct. 2:5, 1959 #1 RECTIFIER 22I a 23 25 H? 30 26 g2; 24 L $26 31 23 l'\ l 10 26 23 Z INVENTOR. HAROLD.ScHAA/KLHZ ATTORA/fX United States Patent This invention relates tocamera flasher systems. It is particularly directed to a speed lightflasher system which may be built into a camera, to be repeatedly used,and employing flash tubes, envelopes, or bulbs, filled with Xenon,argon, neon, or the like gas.

in a conventional fiasher, the capacitor is charged to some high directcurrent value. By triggering such a flash tube with a pulse, the energystored in the capacitor is released to flash the tube.

With A.C., this cannot be done because one never knows where the AC.voltage will be at a particular time, since the voltage continuouslyvaries, for example, at the rate of 60 cycles per second. It is henceone object of the present invention to provide a highly improved cameraflasher system of the character described utilizing AC. house current,with means for triggering the tube a plurality of times in rapidsuccession to ensure triggering at the minimum firing voltage of theflash tube. The tube in my improved system is normally non-conductivethe m; num AC. voltage. However, when triggered with a high voltagepulse or pulses, the gas in the tube ion at and if the triggered voltageimpressed on the pal-nary electrodes of the tube is sufficient, largecurrent flows through the tube to flash the tube, until the voltageacross the primary electrodes drops to a certain minimum value, whichtime the tube will cease to conduct until l Sl'fid again.

The tube, when it conducts, acts as a low impedence. if this were oeratcd off a DC. source, which can supply high current, withoutexcessive voltage drop, then the tube would continue to conductindefinitely until it is destroyed. By using A.C., which is constantlychanging voltage, as soon as the voltage decreases sufficiently, theconduction stops until triggered again.

in one form of the invention, the successive triggerings are obtained bysequential closing of a plurality of capacitor circuits connected inparallel with each other and in series with a transformer, the secondarycoil of which is in circuit with the primary electrodes of the tube.

in another form of the invention, the multiple pulses for thetriggerings, are provided by a transistor oscillating circuit.

Another object of this invention is to provide in a system of thecharacter described, an economical and positive means for ensuringlashing of the tube, which shall be highly efiicicnt in use.

Other objects of this invention will in part be obvious and in parthereinafter pointed out.

The invention accordingly consists in the features of construction, comination of elements, and arrangement of parts, which will be exemplifiedin the construction hereinafter described, and of which the scope ofinvention will be indicated in the following claims.

In the accompanying drawings in which is shown an illustrativeembodiment of this invention,

l is a wiring diagram illustrating one system embodying my invention;and

Fit 2 is a wiring diagram illustrating a system embodying another formof the invention.

erring now in detail to the drawing, and particularly to 1 thereof, Thldesignates a camera flasher system embodying the irwention. in saiddiagram, 12 and i3 designate leads of AC. supply, such as a housecurrent. lead Ill is connected by wire 13, through in- Th e ductance lidto one primary or main electrode 15 of a gas filled tube to, such as anXenon, neon or argon filled flasher tube. The other primary or mainelectrode 15a, of said tube is connected by wire 13 to the other lead 12of said source of AC. current. The purpose of the inductance 14 is tolimit the maximum current through the flash tube.

Lead ill is also connected by Wire ill to a rectifier 21, which isconnected to a wire 22.. Across the wires 22, iii are a plurality ofseries connected resistances 23 and capacitors M, in parallel with eachother. T he junctions between the resistances and capacitors areconnected by wires 2:; to spaced contacts 26 adapted to be contactedsequentially by a shutter leaf 3% of the camera in which this system isincorporated. Said leaf fall may have a linger 31 which will sweepacross the spaced contacts 26 when an exposure is made. The leaf isconnected by wire 32 to one side of the primary coil 33 of a transforme34. The other side of said coil is connected by wire 35 to said wire 18.

One side of the secondary coil 36 of said transformer 34 is connected bywire 37 to the starter electrode l7 of tube 16. The other side of coil36 is connected by wire 33 to said wire 13.

The tube 16 is subject to AC. voltage from the house current but willnot flash until it is subjected to high voltage DC. pulse from thetriggered transformer.

If there were only one capacitor 24 and one contact 26, the circuitthrough the capacitor might be made at a time when the A.C. voltage,which varies continuously, is at a value below the minimum required toeffect a flash.

By making several sequential contacts, if one is made at a time when theAC. voltage is too low, another will be made in such timed relation thatat least one of the contacts 26 is engaged by finger ill at a time whenthe AC. voltage is high enough or sul'licient to cause a flash.

in HS. 2 there is shown a wiring diagram Ma embodying a modified form ofthe invention. in said diagram, 5d designates a transistor. Wire 51connects the base of the transistor to a resistance 52 which isconnected by wire 53 to one side of the primary coil 55 of a transformer5d. The other side of said coil 55' is connected by wire 5'7 to thecollector of the transistor St An intermediate portion of coil 55 isconnected by wire 52; to a shutter leaf 59 of the camera in which thesystem is incorporated. Leaf 5% has a finger as adapted to engage acontact 61 when an exposure is made. Contact 61 is connected by wire 62to one side of a capacitor 63. The other side of the capacitor isconnected by wire 64 to the emitter of the transistor Ell.

Across the capacitor 63 is low voltage DC. battery 65 in series with ahigh value resistance 67. The battery may be 6 volts and the resistance67 may be about 1,000 ohms.

The secondary coil '78 of transformer 56 is connected by Wire '71 to thelead 72 of an AC. supply such as house current. The other side of saidcoil '70 is connected by wire 73 to the starter electrode 74 of a gasfilled flasher to e '75, such as an xenon, argon, neon or the like gasfilled tube. One primary electrode "Id of the tube is connected by wire76 to the lead 77 of the AC. source. Lead 72 is connected by wire '73 tothe other primary electrode "[3 of tube '7 5.

The transistor oscillating circuit provides multiple pulses, and as soonas one of these pulses takes place at a time when the AC. voltage intube is above the minimum required to dash the tube, it will flash. Thetransistor oscillating circuit, it will be noted, will oscillate onlywhile the capacitor 63 is charged above a predetermined valve and fingertl is contacting contact till.

When capacitor 63 has discharged to an extent which brings its chargebelow said predetermined valve, oscillation ceases until the battery 65builds up its charge again, while finger is moved away from contact 61.This arrangement limits the number of pulses to the flasher tube eachtime the capacitor 63 is fully charged, so that the tube will not rundown too fast.

Gnly one contact is necessary on the shutter switch 66, 61, since theoscillations of the transistor circuit provides the repeated pulses.

An inductance similar to inductance 114 of FIG. 1, may be included inthe AC. circuit.

It will thus be seen that there is provided an apparatus in which theseveral objects of this invention are achieved, and which is welladapted to meet the conditions of practical use.

As possible embodiments might be made of the above invention, and asvarious changes might be made in the embodiment above set forth, it isto be understood that all matter herein set forth or shown theaccompanying drawings, is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. In combination, a gaseous discharge tube comprising a transparentenvelope having an ionizable gas sealed therein, a pair of mainelectrodes and an igniter electrode, means to impress at the mainelectrodes, AC. voltage the greatest amplitude of which is insufficientto cause the gas in the envelop to conduct, and means to impress anoscillating voltage from the igniter electrode to one of said mainelectrodes, of such magnitude that when impressed concurrently with asaid AC. voltage of greater amplitude, together, said impressed voltageswill be sufiicient to cause said gas to conduct, and when impressedconcurrently with said A.C. voltage at reduced amplitude, said gas willnot conduct, said means for impressing said oscillating voltageincluding means to insure impressing said oscillating circuit while saidgreater amplitude of said A.C. current is being impressed, to insureconduction of the gas and flashing of the tube, manual means to controlthe means for impressing said oscillating circuit, said manual meanscomprising a camera shutter, said means for impressing oscillatingcircuit including means to repeatedly impress said circuit a pluralityof times, during one movement of said shutter.

2. In combination, a gaseous discharge tube comprising a transparentenvelope having an ioniable gas sealed therein, a pair of mainelectrodes and an igniter electrode, means to impress at the mainelectrodes, A.C. voltage the greatest amplitude of which is insufiicientto cause the gas in the envelop to conduct, and means to impress anoscillating voltage from the igniter electrode to one of said mainelectrodes, of such magnitude that when impressed concurrently with asaid A.C. voltage at greater amplitude, together, said impressedvoltages will be sufficient to cause said gas to conduct, and whenimpressed concurrently with said A.C. voltage at reduced amplitude, saidgas wil not conduct, said means for impressing said oscillati voltageincluding means to insure impressing said oscillating circuit whie saidgreater amplitude of said AC. current is being impressed, to insureconduction of the gas and flashing of the tube, said means to impress anoscillating circuit including a transistor oscillating circuit, means tosupply DC. voltage to said oscillating circuit, manual means to closeand open said oscillating circuit, said means to supply DC. voltageincluding means to self terminate the supply of DC. voltage while themanual means is closed.

3. in combination, a gaseous discharge tube comprising a transparentenvelope having an ionizable gas sealed therein, a pair of spaced mainelectrodes and an igniter electrode spaced from both main electrodes,means to continuously impress AC. voltage on the main electrodes of saidtube, a plurality of capacitors connected in parallel, means to supplyD.C. voltage to said capacitors, a transformer having a primary coil,manually controlled means to cause said capacitors to sequentiallydischarge to said primary coil, and said transformer comprising asecondary coil connected across the igniter electrode and one of saidmain electrodes of said tube, said manually controlled means including acamera shutter element, and means on said element to sequentiallyconnect said capacitors seriatum in circuit with said primary coil assaid element is actuated once for exposure.

4. in combination, a transistor oscillating circuit, means to supply DC.voltage to said oscillating circuit, manual means to close and open saidoscillating circuit, a gaseous discharge tube comprising a transparentenvelope having an ionizable gas sealed therein, two spaced mainelectrodes, and an igniter electrode spaced from bot main electrodes,means to continuously impress AC. voltage across the main electrode oftube, and means to cause said oscillating circuit to repeatedly pulseacross the igniter electrode and one of said main electrodes of saidtube while said oscillating circuit is closed by said manual means andDC. voltage is being supplied by said DC. voltage supply means, and saidmeans to supply DC. voltage including means to self-terminate the supplyof DC. voltage while the manual means is closed.

References Cited in the file or this patent UNITED STATES PATENTS

1. IN COMBINATION, A GASEOUS DISCHARGE TUBE COMPRISING A TRANSPARENTENVELOPE HAVING AN IONIZABLE GAS SEALED THEREIN, A PAIR OF MAINELECTRODES AND AN IGNITER ELECTRODE, MEANS TO IMPRESS AT THE MAINELECTRODES, A.C. VOLTAGE THE GREATEST AMPLITUDE OF WHICH IS INSUFFICIENTTO CAUSE THE GAS IN THE ENVELOP TO CONDUCT, AND MEANS TO IMPRESS ANOSCILLATING VOLTAGE FROM THE IGNITER ELECTRODE TO ONE OF SAID MAINELECTRODES, OF SUCH MAGNITUDE THAT WHEN IMPRESSED CONCURRENTLY WITH ASAID A.C. VOLTAGE OF GREATER AMPLITUDE, TOGETHER, SAID IMPRESSEDVOLTAGES WILL BE SUFFICIENT TO CAUSE SAID GAS TO CONDUCT, AND WHENIMPRESSED CONCURRENTLY WITH SAID A.C. VOLTAGE AT REDUCED AMPLITUDE, SAIDGAS WILL NOT CONDUCT, SAID MEANS FOR IMPRESSING SAID OSCILLATING VOLTAGEINCLUDING MEANS TO INSURE IMPRESSING SAID OSCILLATING CIRCUIT WHILE SAIDGREATER AMPLITUDE OF SAID A.C. CURRENT IS BEING IMPRESSED, TO INSURECONDUCTION OF THE GAS AND FLASHING OF THE TUBE, MANUAL MEANS TO CONTROLTHE MEANS FOR IMPRESSING SAID OSCILLATING CIRCUIT, SAID MANUAL MEANSCOMPRISING A CAMERA SHUTTER, SAID MEANS FOR IMPRESSING OSCILLATINGCIRCUIT INCLUDING MEANS TO REPEATEDLY IMPRESS SAID CIRCUIT A PLURALITYOF TIMES, DURING ONE MOVEMENT OF SAID SHUTTER.